1. Field
The present invention relates to a voice assist apparatus. More specifically, the present invention relates to a voice assist apparatus used with an artificial respiratory device provided with an inspiration gas-inlet tube, an endotracheal tube, and a pressure on-off valve, the pressure on-off valve being connected with the inspiration gas-inlet tube and a first end of the endotracheal tube, the pressure on-off valve being opened up to and closed off from atmosphere at the timings of expiration and inspiration, respectively, of a patient.
2. Description of the Related Art
Conventionally, patients who use an artificial respirator connected with an endotracheal tube endotracheally inserted from an incision in their trachea under their vocal chords breathe with the artificial respiratory device. In this case, since expired air from their lungs during expiration tends to flow to the endotracheal tube, the expired air to flow to their vocal chords is reduced so as to insufficiently vibrate their vocal chords. Therefore, patients who use an artificial respirator hardly vocalize.
Accordingly, a voice assist apparatus include an artificial respiratory device provided with a gas feeder supplying inspiration gas for a patient, an endotracheal tube endotracheally inserted from the trachea incision of a patient, a respiratory tube communicating the gas feeder with the endotracheal tube, and an on-off valve divergingly communicating the respiratory tube with atmosphere; and a vocalization device provided with a voice assist tube with a first end being endotracheally inserted from the trachea incision of a patient, an inlet tube communicating the first end with a supply source of voice assist gas, an on-off valve operated by pressure inside the tubes communicated therewith, the on-off valve communicating the inlet tube with the voice assist tube, and an operation tube connected with the on-off valve to operate the on-off valve, in which the operation tube communicates with the respiratory tube at its middle, and the on-off valve has a valving element operated by pressure inside the operation tube to open and close an opening end communicating the inlet tube with the voice assist tube (Patent Document 1: JP 2009-153775 A).
According to the voice assist apparatus of Patent Document 1, inspiration gas is supplied from the gas feeder to the trachea of a patient through the respiratory tube and filled in the lungs of a patient to pressurize the inside of the respiratory tube, during expiration. When the inside of the respiratory tube is pressurized, the pressure inside the operation tube communicating with the respiratory tube increases to operate the valving element of the on-off valve and close the open end communicating the inlet tube with the voice assist tube.
On the other hand, when the inside of the respiratory tube is depressurized to approximate atmospheric pressure during expiration of a patient, the pressure inside the operation tube communicating with the respiratory tube decreases. When the pressure inside the operation tube decreases, the valving element of the on-off valve connected with the operation tube is operated to open the open end communicating the inlet tube with the voice assist tube.
Then, voice assist gas that has been supplied from the inlet tube is introduced to the voice assist tube and the trachea of a patient to flow to and vibrate the vocal chords of a patient for vocalization.
As mentioned above, in the voice assist apparatus of Patent Document 1, the operation tube closes the on-off valve when the inside of the respiratory tube is pressurized during expiration of a patient. On the other hand, the operation tube opens the on-off valve when the pressure inside of the respiratory tube is decreased by communicating with atmosphere during inspiration of a patient. Then, voice assist gas is supplied to the trachea of a patient to vibrate the vocal chords of a patient for vocalization.
Therefore, the patients do not need complex operation at every expiration but can vocalize during expiration and have a conversation in a near-natural voice.